title: At what age does low back pain become a common problem? A study of 29,424 individuals aged 12-41 years.
abstract: METHODS
  A cross-sectional study was performed in a Danish population of individuals 12-41 years of age.
  
  
  OBJECTIVE
  To study the lifetime cumulative incidence, the 1-year period prevalence, and point prevalence of low back pain in the general population and to investigate whether there were any differences in the occurrence of low back pain that were related to age and gender, especially in young individuals.
  
  
  BACKGROUND
  The epidemiologic literature fails to provide a credible estimate of the prevalence of low back pain in children and adolescents compared with that of adults.
  
  
  METHODS
  A postal questionnaire was sent to 34,076 twins who were born between 1953 and 1982 and listed in the population-based Danish Twin register. The response rate was 86%.
  
  
  RESULTS
  The prevalence of the various definitions of low back pain increased greatly in the early teen years (earlier for girls than for boys), and by the ages of 18 years (girls) and 20 years (boys) more than 50% had experienced at least one low back pain episode. The pattern for the 1-year period prevalence of low back pain was very similar to that for the lifetime prevalence; both started at 7% (95% confidence interval, 5-9%) for the 12-year-old individuals and reached 56% (95% confidence interval, 53-59%) and 67% (95% confidence interval, 62-71%), respectively, for the 41-year-old individuals. The pattern for the point prevalence resembled that of the more than 30 days of low back pain reported in the preceding year; the rate increased steadily from 1% (95% confidence interval, 0-2%) to 1.7% (95% confidence interval, 14-20%). There was a general tendency for more women to report low back pain than men, but this difference generally was not statistically significant.
  
  
  CONCLUSIONS
  The study of the causes and prevention of low back pain needs to be focused on childhood and adolescence.
authors.affiliation: Nordic Institute for Chiropractic and Clinical Biomechanics, Odense University, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Leboeuf-Yde
authors.forename: K O
authors.initials: KO
authors.lastname: Kyvik
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001416:Back Pain / Q000453:epidemiology*; D002648:Child; D003430:Cross-Sectional Studies; D003718:Denmark; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D017678:Sex Distribution